Recently, various molded articles such as housings for electronic devices, e.g., housings for so-called “mobile phone” and housing for printers, have been recycled. There are cases that various pressure-sensitive adhesive labels, so-called nameplate labels, for indicating product information such as name of manufacturer, name of country of manufacture, name of product, product number, and product lot number are attached to electronics devices. When a pressure-sensitive adhesive label has been attached to an electronics device as above, in the case that the raw material of the housing of the electronic device is different from the raw material of the pressure-sensitive adhesive label, the raw material of the pressure-sensitive adhesive label may be incorporated into the raw material of the housing of the electronic device when the label is not peeled off at its recycle. Thus, physical properties of the recycled raw material may vary in some cases. For example, in the case that the raw material of the adherend (molded article) to be attached is a styrene-based resin, when the raw material of the substrate of the pressure-sensitive adhesive label is a polyester-based resin such as polyethylene terephthalate, a styrene-based resin is low in compatibility with a polyester-based resin, so that reproduction of the plastic (adherend derived from the styrene-based resin) with the pressure-sensitive adhesive label attached thereto results in insufficient strength of a molded article from the reproduced plastic and/or generation of defect(s) in appearance. Therefore, as the pressure-sensitive adhesive label, there has been developed a label using, as the raw material of the substrate, the same raw material or the same kind of raw material as the raw material of the adherend (molded article) to be attached or a raw material having a good compatibility therewith. For example, since a housing for electronic devices uses a styrene-based resin such as an acrylonitrile-butadiene-styrene-based copolymer, there has been proposed an pressure-sensitive adhesive label using a styrene-based resin such as polystyrene, an acrylonitrile-butadiene-styrene copolymer, or an acrylonitrile-styrene-acrylic rubber copolymer as the raw material for the substrate (see JP-A-8-67857, JP-A-2000-338882 (the term “JP-A” as used herein means an “unexamined published Japanese patent application”) and JP-T-2003-521719 (the term “JP-T” as used herein means an “unexamined published International patent application”)).
When a pressure-sensitive adhesive label was attached to the housing for an electronics device by mistake at the attachment of the label or when a trouble arises in the electronics device after the pressure-sensitive adhesive label is attached to the housing of the electronic device, in order to peel off the pressure-sensitive adhesive label to use the housing of the electronics device again, a pressure-sensitive adhesive label which is capable of easily being peeled off and does not leave any component of the pressure-sensitive adhesive on the surface of the adherend after peeling (without so-called “adhesive residue”) has been desired. That is, a pressure-sensitive adhesive label having a good reworkability has been desired.